This renewal application is for funds to continue an investigation of the research project EY O1821-03 (which terminates on 01/31/80) on the biochemistry, biosynthesis and intermediary metabolism of lenticular sphingolipids. Details will be sought about the assays, purification and enzymatic properties of human lenticular ceramide synthetase and ceramidase, and the mode of action of an inhibitor of ceramide synthesis will be determined. Procedures, such as affinity chromatography, will be developed to aid in the purification of these enzymes. New procedures will be developed to cultivate lens epithelium of normal lenses and senile cataracts in vitro, so that the metabolic fate (incorporation and turnover studies) of lenticular ceramides and fucoglycosphingolipids can be determined. Studies will be continued on the isolation, purification and chemical characterization of a novel fucose-containing glycosphingolipid from human lenses. Techniques, such as HPTLC plates, will be used to obtain a better separation of these compounds from the lenses.